Novel matrix formulation for resin composite: Chemical and biomechanical characterization - Part 1.

Objective: This study aimed to investigate the effects of adding cholesteryl methacrylate (CM) monomer to experimental composite resins and evaluate its impact on polymerization shrinkage force (PSF), Knoop microhardness (KHN), sorption and solubility (SS), vulnerability to spontaneous oxidation (VOE), porosity (BES), viscosity (V), and cross-link density (CLD). CM was synthesized, mixed with varying proportions of Bis-GMA, 70 wt% filler particles, and 40 % TEGDMA. The groups tested were: CM0 (60 % Bis-GMA), CM6 (54 % Bis-GMA/6 % CM), CM12 (48 % Bis-GMA/12 % CM), CM18 (42 % Bis-GMA/18 % CM) and CM24 (36 % Bis-GMA/24 % CM).

Socket shield technique: Stress distribution analysis.

Background: To analyze through finite element analysis the stress distribution in peri-implant bone tissues, implants, and prosthetic components induced by the socket shield (SS) technique in comparison to other techniques used to treat tooth loss.

Materials And Methods: A three-dimensional model of a superior central incisor crown supported by implant was modeled and three different placement conditions were simulated: SS - 2.0-mm-thick root dentin fragment positioned between the alveolar buccal wall and implant; heterologous bone graft (HBG) - bovine bone graft positioned the alveolar buccal wall and implant; and control (C) - implant fully placed in bone tissue of a healed alveolus.

The effect of the die material used in the indirect technique on the fracture resistance of a restored molar.

The aim of this study was to evaluate the effect of different die materials used in the indirect resin composite restorative technique on the fracture resistance and failure mode of restored molars and compare it with the direct resin composite restorative technique. Two flexible die silicone materials for dental models (Die Silicone - Voco and Scan die - Yller) and a type IV dental stone material (Fujirock EP - GC) were evaluated. Sixty third molars were selected and divided into four groups: indirect resin composite restoration - Die silicone (IRCR-DS); indirect resin composite restoration - Scan die (IRCR-SD); indirect resin composite restoration - Fujirock EP (IRCR-FR), and direct resin composite restoration (DRCR).

The parental psychological distress caused by separation from their critically ill child during the COVID-19 pandemic: A tale of two cities.

Introduction: A child's critical illness is a stressful event for the entire family, causing significant emotional distress among parents and changes to family functioning. The Severe Acute Respiratory Syndrome-Related Coronavirus 2 (SARS-CoV-2) pandemic has abruptly caused modifications in visitation policies of Pediatric Intensive Care Units (PICUs) in many countries. We hypothesized that caregivers with no or severely restricted access to PICUs would demonstrate increased psychological distress as compared to those who had limitless access (LA) to PICUs.

Efficacy of two low-level laser therapy protocols following lower third molar surgery - a randomized, double-blind, controlled clinical trial.

The aim of this study was to test two low-level laser therapy protocols by evaluating pain control, swelling and trismus in the postoperative period of lower third molar surgeries. This was a randomized, double-blind, placebo-controlled, crossover trial. Patients presenting two symmetrically impacted mandibular third molars were included.

Attitudes of dentists toward maintaining, repairing, or replacing direct composite resin restorations.

This study aimed to report the reasons for replacement of direct composite resin restorations in dental practices in Brazil. The study used a convenience sample of 213 dentists. A questionnaire was developed from previously validated instruments and sent electronically to prospective participants.

Is Zirconia Better Than Titanium Abutments for Soft Tissue Color? A Systematic Review and Meta-analysis of Spectrophotometric Evaluation.

Purpose: The aim of this systematic review was to evaluate the influence of zirconia and titanium as abutment materials on peri-implant soft tissue color.

Materials And Methods: The searched electronic databases included MEDLINE/PubMed, LILACS, Web of Science, Scopus, and LIVIVO. Two types of studies were included: randomized clinical trials (RCTs) and controlled clinical trials (CCTs) that compared zirconia (Zr) and titanium (Ti) abutments.

Facial profile changes due to bone cement graft to manage the hyperactive muscles of the gingival smile.

Objective: To evaluate facial profile changes promoted by polymethyl methacrylate (PMMA) cement graft to reduce excessive gingival display due to hyperactivity of the elevator muscles of the upper lip during smiling.

Methods: Eleven patients (all females, age range: 20 to 43 years) presenting gingival smile that were treated with PMMA cement grafts in a private clinic were selected for this retrospective study. Three angular and ten linear cephalometric facial profile measurements were performed preoperatively (baseline, T1) and at least 6 months postoperatively (T2).

Influence of different application protocols of universal adhesive system on the clinical behavior of Class I and II restorations of composite resin - a randomized and double-blind controlled clinical trial.

Background: Multimode adhesives incorporate the versatility of adapting to various clinical situations by its capacity to be used in different protocols. This study aimed to evaluate the clinical behavior of composite resin direct restorations (Class I and II) performed with different universal dentin adhesive application protocols comparing adapted FDI and adapted USPHS criteria.

Methods: The current study is a randomized, double-blind, split-mouth, and convenience sample controlled clinical trial.

Comparison of Dimensions of the Nasopharynx and Oropharynx Using Different Anatomical References: Is There Equivalence?

Purpose: To evaluate the equivalence of the volumes obtained using different anatomic references to measure the nasopharynx and oropharynx on cone-beam computed tomography (CBCT) scans. We hypothesized that no variations would be found in the nasopharynx and oropharynx dimensions when measured using different measurement methods.

Materials And Methods: A total of 40 CBCT scans of patients with skeletal Class I (age range, 20 to 50 years) were measured independently by 2 of us.

Contribution of cone-beam computed tomography in the decision of surgical management for bone lesions of the maxillofacial region.

The aim of this study was to evaluate the contribution of cone-beam computed tomography (CBCT) in the decision of surgical management for bone lesions of the maxillofacial region. It is a retrospective cross-sectional observational study that includes a sample of panoramic radiography (PR) and CBCT from patients with some type of bone lesion in the maxillofacial region. PR and CBCT images were evaluated by three previously assessed examiners, specialists in oral and maxillofacial surgery.

Resin Cement: Correspondence with Try-In Paste and Influence on the Immediate Final Color of Veneers.

Purpose: To assess the correspondence of shades between try-in pastes and resin cements and their influence on the final color of veneers.

Materials And Methods: Bovine teeth (n = 140) were prepared and divided into 2 groups (a or b) according to ceramic veneer thickness (0.35 or 0.

Four-year follow-up of a polymethyl methacrylate-based bone cement graft for optimizing esthetics in maxillary anterior implants: a case report.

Tooth loss promotes bone and gingival tissue remodeling, thus breaking the harmony between the residual ridge and natural teeth. This is critical in the anterior region of the mouth, and the integration of several dental specialties is often essential to successful rehabilitation with implants. This article describes a multidisciplinary approach to implant-supported oral rehabilitation in the maxillary anterior region, presenting a new technique for optimizing esthetics in implants.

Maxillary canine morphology: comparative and descriptive analysis from periapical radiographs and cone beam computed tomography.

The anatomical characteristics of permanent maxillary canines were evaluated through visual examination, periapical radiography, and cone beam computed tomography (CBCT), and measurements obtained from the images and directly on the teeth were compared. Fifty extracted human maxillary canines were classified according to the side of the mouth. The direction of root curvature and location of the apical foramen were also verified.

Screening the use of informed consent forms prior to procedures involving operative dentistry: ethical aspects.

The present study aimed to screen the knowledge and attitudes of dentists toward the use of informed consent forms prior to procedures involving operative dentistry. A research tool containing questions (questionnaire) regarding the use of informed consent forms was developed. The questionnaire consisted of seven questions structured to screen the current practice in operative dentistry towards the use of informed consent forms.

Ozone Gas Effect on Mineral Content of Dentin exposed to Streptococcus mutans Biofilm: An Energy-dispersive X-ray Evaluation.

Aim: This study aims to assess the effect of ozone gas on dentin exposed to Streptococcus mutans biofilm by evaluation of mineral content [log calcium-to-phosphorus (Ca/P)] using energy-dispersive X-ray (EDX) spectroscopy.

Materials And Methods: Five human third molars were sectioned into four slices of dentin and distributed in four groups: I - control (no treatment); II - ozone therapy; III - biofilm development; IV - ozone therapy followed by biofilm development. Mineral content (log Ca/P) was evaluated by EDX.

Inflammatory response of human dental pulp to at-home and in-office tooth bleaching.

Objective:: This study evaluated the inflammatory responses of human dental pulp after the use of two bleaching techniques.

Material And Methods:: Pulp samples were collected from human third molars extracted for orthodontic reasons and divided into three groups: control - no tooth bleaching (CG) (n=7); at-home bleaching with 15% carbamide peroxide (AH) (n = 10), and in-office bleaching with 38% hydrogen peroxide (IO) (n=12). Pulps were removed and stained with hematoxylin-eosin for microscopic analysis of inflammation intensity, collagen degradation, and pulp tissue organization.

Effect of Genioplasty on the Pharyngeal Airway Space Following Maxillomandibular Advancement Surgery.

Purpose: To evaluate the effect of genioplasty on the size of the pharyngeal airway space (PAS) in a sample of patients without obstructive sleep apnea syndrome (OSAS) undergoing maxillomandibular advancement (MMA) surgery.

Materials And Methods: Lateral cephalometric radiographs of 52 patients who underwent orthognathic surgery for MMA were obtained before (T1) and after (T2) surgery. The radiographs were digitized and the anteroposterior dimensions of the PAS were measured at the nasopharynx, oropharynx, and hypopharynx levels.

Try-in Pastes Versus Resin Cements: A Color Comparison.

This study aimed to compare the color of ceramic veneer restorations using different shades of try-in pastes and resin cement. Researchers found no differences between try-in pastes and resin cements after cementation.

Shade evaluation of ceramic laminates according to different try-in materials.

The porcelain laminate replaces the visible portion of enamel with a ceramic, which is attached to the dental surface. To enhance cosmetic results, a preliminary color matching procedure is performed prior to cementing the veneers. This procedure can be performed using water, water-soluble gel, or try-in paste.

Comparison of the correlation of photoelasticity and digital imaging to characterize the load transfer of implant-supported restorations.

Statement Of Problem: Whether splinting or not splinting adjacent implants together can optimize the stress/strain transfer to the supporting structures remains controversial.

Purpose: The purpose of this study was to compare the photoelasticity and digital image correlation (DIC) in analyzing the stresses/strains transferred by an implant-supported prosthesis.

Material And Methods: A polymethylmethacrylate model was made with a combination of acrylic resin replicas of a mandibular first premolar and second molar and threaded implants replacing the second premolar and first molar.

Effect of acetyl resin retentive arms on the retentive force of circumferential clasps: an in vitro study.

Purpose: To compare and to evaluate the stability of the retentive force of cobalt-chromium (Co-Cr) circumferential clasps (control) to those with an acetyl resin retentive arm.

Methods: Sixteen specimens with a couple of circumferential clasps were made using Co-Cr over a metal model providing 0.25 mm undercuts.

Correlation between vertical misfits and stresses transmitted to implants from metal frameworks.

An inappropriate prosthetic fit could cause stress over the interface implant/bone. The objective of this study was to compare stresses transmitted to implants from frameworks cast using different materials and to investigate a possible correlation between vertical misfits and these stresses. Fifteen one-piece cast frameworks simulating bars for fixed prosthesis in a model with five implants were fabricated and arranged into three different groups according to the material used for casting: CP Ti (commercially pure titanium), Co-Cr (cobalt-chromium) or Ni-Cr-Ti (nickel-chromium-titanium) alloys.

Photoelastic stress analysis of different designs of cement-retained fixed partial dentures on Morse taper oral implants.

There is no consensus in literature regarding the best plan for prosthetic rehabilitation with partial multiple adjacent implants to minimize stress generated in the bone-implant interface. The aim of this study was to evaluate the biomechanical behavior of cemented fixed partial dentures, splinted and nonsplinted, on Morse taper implants and with different types of coating material (ceramic and resin), using photoelastic stress analysis. A photoelastic model of an interposed edentulous space, missing a second premolar and a first molar, and rehabilitated with 4 different types of cemented crowns and supported by 2 adjacent implants was used.

Effects of early functional loading on maintenance of free autogenous bone graft and implant osseointegration: an experimental study in dogs.

Purpose: The aim of the present study was to investigate the healing, integration, and maintenance of autogenous onlay bone grafts and implant osseointegration either loaded in the early or the delayed stages.

Materials And Methods: A total of 5 male dogs received bilateral blocks of onlay bone grafts harvested from the contralateral alveolar ridge of the mandible. On one side, the bone block was secured by 3 dental implants (3.